Field of the Invention
Embodiments of the invention generally relate to an electrostatic chuck and process kit for a semiconductor processing chamber, and a semiconductor processing chamber having a process kit. More specifically, embodiments of the invention relate to a process kit including at least a deposition ring used in a physical vapor deposition chamber. Other embodiments relate to a deposition ring for use with a flangeless electrostatic chuck and processing chamber having the same.
Description of the Related Art
Physical vapor deposition (PVD), or sputtering, is one of the most commonly used processes in the fabrication of electronic devices. PVD is a plasma process performed in a vacuum chamber where a negatively biased target is exposed to a plasma of an inert gas having relatively heavy atoms (e.g., argon (Ar)) or a gas mixture comprising such inert gas. Bombardment of the target by ions of the inert gas results in ejection of atoms of the target material. The ejected atoms accumulate as a deposited film on a substrate placed on a substrate support pedestal disposed within the chamber.
An electrostatic chuck (ESC) may be used to support and retain substrates within the processing chamber during processing. The ESC typically includes a ceramic puck having one or more electrodes therein. A chucking voltage is applied to the electrodes to electrostatically hold the substrate to the ESC. Further information on ESC's can be found in U.S. Pat. No. 5,909,355, issued Jun. 1, 1999.
A process kit may be disposed in the chamber to help define a processing region in a desired region within the chamber with respect to the substrate. The process kit typically includes a cover ring, a deposition ring, and a ground shield. Confining the plasma and the ejected atoms to the processing region helps maintain other components in the chamber free from deposited materials and promotes more efficient use of target materials, as a higher percentage of the ejected atoms are deposited on the substrate.
Although conventional ring and shield designs have a robust processing history, improvements in film uniformity and throughput are constantly desired. Existing process kit designs position components in close proximity to the substrates during processing. The close proximity of the process kit components can affect the electric fields around the substrates and alter the uniformity of the films being deposited near the edge of the substrates.
Therefore, there is a need in the art for an improved process kit.